1. Field of the Invention
This invention pertains to a sublethal assay to determine environmental quality, and in particular, stress induced through alterations or degradation of the environmental quality. More specifically, organisms in the environment to be studied are assayed for the presence of specific or selected proteins, produced in response to stress. The assay may be used to identify the type of stressor present, or class of stressors.
2. Background of the Prior Art
The continuing and increasing encroachment of industry and civilization on valuable and critical environments inevitably results in a conflict between the ecosystem's ability to maintain a stable environment hospitable to the plants, animals and individuals inhabiting that environment, and the ability of an the industrial complex to distribute or dispose of its waste material, including toxic materials, and environmental pollutants. It is becoming increasingly critical to be able to assay, or periodically sample, the environmental quality, to determine the presence of pollutants, at an early stage, and accordingly take measures to prevent further degradation of the environment. The environment may be aquatic, land, or airborne, or a mixture. It is important to provide an assay system to determine environmental quality that is relatively rapid, low cost, and yet can determine the presence of pollutants at a very early stage and low levels. It would be desirable to provide a system which can provide quantitative measurement of the pollutant and qualitative information as well, such as the type of pollutant actually causing the stress or toxicity.
Some prior art environmental assays are confined to lethal assays. That is, specific laboratory animals are generally exposed to concentrations of the pollutant found in the environment, or actual samples of the environment itself. If the animal or organism survives exposure, it is considered presumptive evidence of no pollution.
One principal drawback to such systems is that acute lethal affects are rarely observed in the field. In general, there is a slow loss of population, corresponding to a gradual increase in or long term exposure to, pollution, until the point at which lethal responses are observed and identified, which is generally beyond the point of no return. In any event, the pollutant or stressor has no gross observable effect (mortality) on the organism at the time of the test. In general, such assays serve only to confirm the investigator's suspicion that there is an environmental pollutant, and that the disappearance of the organism in the environment is not due to some alternative, unexplained natural cause. Other assays require extended exposure (and expense) or sophisticated procedures or equipment not easily accessible.
Accordingly, it remains an objective of the industry to provide an assay based on some criterion other than lethality, or requiring prolonged exposure or impractical end points which can detect the presence of environmental pollutants, or environment changes below lethal levels, give some type of quantitative information regarding the presence of the pollutant, and certain qualitative information, concerning the identity of the pollutant. Environmental managers and aquaculturists may further desire a simple measurement of the health of an organism (commercial animal, human population or other biota).